The proportional hazard model uses multiple variables to synthesize multiple parameters to predict the remaining useful life of the system. However, because the traditional proportional hazard model is based on the assumption that multiple research samples are independent and identically distributed, that is, the basic failure rate is the same, but for aero engines, there are differences in basic failure rates due to different operating environments and uses. Studies have shown that ignoring differences between samples can lead to serious bias in the estimates. To this end, this study will introduce the concept of frailty that is used to express the non-independence between samples, and establish a more general vulnerability proportional hazard model for aircraft engines, which will be used for the first time to predict the remaining useful life of aircraft engines. The example shows that the average error of the prediction results based on the proportional hazard model with frailty is 4.6%, while the average error of the prediction results based on the traditional proportional hazard model is 6.9%, which verifies the effectiveness of the proportional hazard model with frailty in the prediction of the remaining useful life of aero engine.